Meeting Abstract

P2.24  Thursday, Jan. 5  Gas exchange and hatching success in loggerhead turtle nests in Greece SUSS, J.S.; PATEL, S.; NEEMAN, N.; PANAGOPOULOU, A.; RIGGALL, T.; MARGARITOULIS, D.; O'CONNOR, M.P.*; SPOTILA, J.R.; Drexel Univ.; Drexel Univ.; Drexel Univ.; ARCHELON; ARCHELON; ARCHELON; Drexel Univ.; Drexel Univ.

Metabolism is important to embryonic development in oviparous reptiles and is influenced by gas exchange, hydric, thermal, and maternal conditions, and nest density. Many reptiles deposit their eggs underground where gas exchange is limited by the diffusive properties of the substrate. Since these clutches cannot move, the air and water in the sand immediately surrounding the nest influences metabolism. Loggerhead turtles bury their clutches 40 cm deep in the beaches along Laganas Bay, Zakynthos and southern Kyparissia Bay, Western Peleponnese, Greece. These beaches differ markedly in sand particle size and nest density, both of which can influence respiratory gas exchangess. During the summers of 2009 and 2010, we measured the physical characteristics of the sand on these beaches, temperatures, oxygen and carbon dioxide levels in nests and hatching success of loggerhead nests. In both years, hatching success was lower at one of the sectors in Kyparissia than all other beaches due to a higher rate of death at a late developmental stage. During incubation on all beaches, oxygen concentration decreased down to 16% and carbon dioxide increased up to 5% in the nests shortly before hatching. Water content at nest depth did not differ between the beaches and was 3.5 +/- 0.34(SE)% moisture and the dry surface sand reached down to an average depth of 19.3 +/- 1.2 cm. Nest temperatures differed among the beaches, affecting sex ratios and incubation duration, but not mortality. Egg mass, hatchling size and clutch size did not differ between beaches, including the beach with the lower hatching success. These results do not explain the lower hatching success on Kyparissia, suggesting that an anthropogenic disturbance had been occurring there.